LEAP Ratios and Proportional Relationships 3

Question 1

A table shows that y is proportional to x. When x = 4, y = 20. What is the constant of proportionality?

Accepted Answer

5

Answer

The constant of proportionality k = y/x = 20/4 = 5.

Question 2

Which graph represents a proportional relationship?

Accepted Answer

A straight line passing through the origin

Answer

A proportional relationship is represented by a straight line that passes through the origin (0, 0).

Question 3

At a bake sale, 4 cookies cost $2.00. Complete the table: how much do 10 cookies cost?

Accepted Answer

$5.00

Answer

Each cookie costs $2.00 ÷ 4 = $0.50, so 10 cookies cost 10 × $0.50 = $5.00.

Question 4

A proportion states: 6/x = 18/27. What is the value of x?

Accepted Answer

9

Answer

Cross-multiplying gives 6 × 27 = 18x, so 162 = 18x, and x = 9.

Question 5

A 12-ounce juice bottle contains 42 calories. How many calories are in a 20-ounce bottle of the same juice?

Accepted Answer

70

Answer

The unit rate is 42/12 = 3.5 calories per ounce; 20 × 3.5 = 70 calories.

(LEAP) Louisiana Educational Assessment Program Practice Test